Tennis Court Corner Marker

ABSTRACT

A device for marking the corner demarcation lines of a tennis court that facilitates identifying whether a ball lands inbounds or out-of-bounds.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of, and claims the benefit of priority to, U.S. patent application Ser. No. 15/058,686, filed on Mar. 2, 2016, entitled “Corner Markers”, and incorporated by reference in its entirety herein, which in turn claims the benefit of priority of U.S. Non-Provisional Patent Application Ser. No. 62/127,143, filed on Mar. 2, 2015, entitled “Corner-shape Markers”, the contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a device for marking the corner demarcation lines of a tennis court that facilitates identifying whether a ball lands inbounds or out-of-bounds.

Discussion of the Background

It is well known that the playing area of a tennis court is defined with colored zones divided by white stripes, wherein said white stripes are combined to define the boundaries of each zone. While playing the game some of the white stripes are part of the playing zone, however the continuity or some of the length of the white stripes belongs to the part of the court considered as the out of bounds area. Therefore, one of the difficulties encountered with the stripe system and the zones definition is the clear definition of out of bound zones. For example, while playing tennis, and more particularly at the moment of serving to an opponent, the boundary between the left and right serve-receiving zones at which a ball landing on the center stripe is considered in bounds for both zones. The problem with the white center stripe is that one of the distal ends is not clearly separated between the playing zone and the out of bounce zone. Therefore, the use of boundary lines marked with a stripe, makes it harder to judge the exact point of impact of the ball when relying solely on eyesight. Particularly if the ball falls at one of the corners of the court. Approximately 50% of the plays wherein the ball bounces at the part of the stripes which are considered in bounds for both zones during a regular game are called erroneously due to problems in judges' perception.

Some sophisticated devices, such as cameras, are used for defining if a ball bounce is in or out of a particular zone. For example, U.S. Pat. No. 5,059,944 discloses an optical system for detecting and signaling a ball out-of-bounds condition on a tennis court. The sensor units are configured around the tennis court in sets of units referred to as optical lattices. Each optical lattice provides intersecting light beams allowing for continuity in court coverage when a player disables a timed plane. An out-of-bounds ball is signaled by an audiovisual device. However, the uses of optical sensors, such as cameras, are complex and expensive. The changes on the court are countless when adding optical sensors to the court.

On another hand, U.S. Pat. No. 4,045,022 discloses a tennis court wherein the different playing zones are distinguished by colors instead of white stripes. The main disadvantage of such disclosure is that the colored playing zones would be less wide than a regular tennis court. This because in a playing zone defined by a white stripe the players may use the outer corner of said white stripe, that usually have a dimension of 2 inches by 2 inches, as an in-bound for the zone. In contrast, in a playing zone defined by color the white stripe is erased, and the colored playing zones are expanded one inch to the right and one inch to the left. In that case, the playing zone for serving the ball will be smaller because the player cannot use the outer corner of the white stripe.

Therefore, there is a need for improving the demarcation lines of a tennis court; and particularly the corners of these lines, in a manner that helps line judges to pin point the exact area of impact of the ball by eye during the games without the need of expensive devices. The present invention could further be used in combination with some other optical, cameras or sensor devices.

SUMMARY OF THE INVENTION

A tennis court marker configured to be inserted into the intersecting lines of demarcation of a tennis court, comprising a cross-piece having the shape of a cross with an opening at its point of intersection; wherein the cross-piece includes a vertical section and a horizontal section that are perpendicular to each other; wherein the vertical section is subdivided into an upper panel and a bottom panel; wherein each panel in the vertical section includes a top surface; wherein the upper panel includes a first leg extending perpendicularly from a first end of the top surface of the upper panel and a second leg extending perpendicularly from a second end of the top surface of the upper panel; wherein the bottom panel includes a first leg extending perpendicularly from a first end of the top surface of the bottom panel and a second leg extending perpendicularly from a second end of the top surface of the bottom panel; wherein the horizontal section is subdivided into a left panel and a right panel; wherein each panel in the horizontal section includes a top surface; wherein the right panel includes a first leg extending perpendicularly from a first end of the top surface of the right panel and a second leg extending perpendicularly from a second end of the top surface of the right panel; wherein the left panel includes a first leg extending perpendicularly from a first end of the top surface of the left panel and a second leg extending perpendicularly from a second end of the top surface of the left panel; wherein an end of the first leg of the left panel is seamlessly connected to an end of the first leg of the upper panel, wherein an end of the second leg of the left panel is seamlessly connected to an end the first leg of the bottom panel, wherein an end of the first leg of the right panel is seamlessly connected to an end of the second leg of the upper panel, and wherein an end of the second leg of the right panel is seamlessly connected to an end of the second leg of the bottom panel, thereby creating the opening at the point of intersection of the cross-piece and providing access to and visibility to the surface of the tennis court.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a tennis court identifying the T-junctions.

FIG. 2A and FIG. 2B are a top views of a tennis court while playing with exploded view of a T-junction,

FIG. 3 is a top view of a first exemplary structure of a tennis court with exploded view of the T-junctions.

FIG. 4 is a top view of a second exemplary structure of a tennis court with exploded view of the T-junctions.

FIG. 5 is an exploded view of the T-junction with the T-intermission of the present disclosure in accordance with the principles of the preferred first embodiment.

FIG. 6 is an exploded view of the T-junction with the T-intermission of the present disclosure in accordance with the principles of the preferred second embodiment.

FIGS. 7A and 7B are an exploded view of the T-junction with the T-intermission of the present disclosure in accordance with the principles of the preferred third embodiment.

FIGS. 8A-8C are exploded views of the T-junction with the T-intermission while the ball is hitting floor in accordance with the principles of the preferred first embodiment, second embodiment and third embodiment.

FIGS. 9A-9B are view of the deformable T-intermission being hit by the ball in accordance with the principles of the preferred first embodiment.

FIG. 10 is a side view of a tennis court marker, in accordance with the principles of the present invention.

FIG. 11 shows and expanded view of the bottom of the court marker, in accordance with the principles of the present invention.

FIG. 12 shows a perspective bottom view, in accordance with the principles of the present invention.

FIG. 13 shows a perspective top view of the court marker, in accordance with the principles of the present invention.

FIG. 14 shows another perspective bottom view of the court marker, in accordance with the principles of the present invention.

FIG. 15 shows the court marker being inserted in of the corners of a tennis court, in accordance with the principles of the present invention.

FIG. 16 shows the locking mechanism of the court marker while the marker is inserted into the, in accordance with the principles of the present invention.

FIG. 17 shows a perspective top view of another embodiment of the court marker, in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is directed to and exemplary playing ground 1, such as a tennis court, wherein said tennis court comprises pavement P and white strips 1 a, wherein said white stripes are arranged to define the playing area generating T-junctions 2 a, 2 b, 2 c. As mentioned before, it is well known that the surfaces, more particularly the playing area of tennis courts, are pave with a uniform color/material and the boundaries of the various playing zones are accomplished by stripes 1 a on the court surface, which usually have a dimension of 2 inches by 2 inches. The pavement, stripes dimensions and boundaries may change depending on particular times of the game. Further the inbound zone, more particularly while serving, change depending on the side a player is serving. For example, as shown in FIG. 2A, one of the various playing zones defined by using the white stripe system of zone definition, is the boundary between the left serve-receiving zone LS and right serve-receiving zone RS at which a ball landing on the center stripe CS is considered in bounds for both zones. However, when the ball 5 lands on a section close to the T-junctions 2 c, as shown in FIG. 2B, more particularly the T-junction at the center stripe CS it is extremely difficult to determine if it was out or in of the playing zone due to the proximity to the continuous stripe segment. Furthermore, the segment is not defined by a line. The exploded view of T-junction 2C at the court center present difficulties of distinguishing the in zone (limited by an imaginary line IM) at the right serve-receiving zone RS when a first player 51 serves to a second player 52.

FIG. 3 is directed to a first exemplary embodiment wherein a T-intermission 3 comprising a third indicia, such as a different material visually different from the color used for the white stripes and of the pavement of the court, is located at the intersection of at least two white strips in T-junctions 2 a, 2 b and 2 c. In this manner, it will be very easy to determine if the ball bounced in the in zone area. No imaginary line IM has to be inferred to make the judgment.

FIG. 4 is directed to a second exemplary embodiment for the present disclosure explained in more detail below. For the second exemplary embodiment the white stripes in the T-junctions 2 a, 2 b, 2 c are extended for about 2 inches and a T-intermission 3 is located at the intersection of at least two white strips in T-junctions 2 a, 2 b and 2 c. In this embodiment, the color of the T-intermission 3 comprises an indicia, such as a different material visually different from the color used for the white stripes but may be the same color and/or material of the pavement of the court. In this manner, this second embodiment comprises only of two colors (the white stripes and the color of the pavement of the court). This in contrast with the first embodiment that comprises at least three different colors (the white strips, the color of the pavement of the court and the color of the indicia).

FIG. 5 is directed to an exploded view of the T-junction 2 c with the T-intermission 3 of the present disclosure in accordance with the principles of the preferred first embodiment. The T-intermission 3 is shaped to simulate the corner of a playing zone. The dimension of the T-intermission 3 depends on the white stripe 1 a, 1 b dimensions, for example the first width W1 of a first white stripe 1 a defines at least one side of the T-intermission 3 while a second width W2 of a second white stipe 1 b defines at least another side of the T-intermission 3. The T-intermission 3 comprises particular indicia, wherein said particular indicia is distinctive from the stripe segment indicia and of the court indicia. For example, in a tennis court configured of mainly green pavement with white stripes, T-intermission 3 could be made with a color such as orange, gold, blue or red, amongst others. The difference in visual perception assist the player, line judge and game spectators to distinguish easily if a ball 5 hits the T-intermission 3, in zone or out zone.

FIG. 6 is directed to an exploded view of the T-junction with the T-intermission of the present disclosure in accordance with the principles of the preferred second embodiment as shown in FIG. 4. The preferred second embodiment comprises a T-Mark 4. The T-Mark 4 is configured by extending the white stripe about 2 inches from the zone boundaries in T-junctions 2 a, 2 b and 2 c.

For example, in FIG. 6 the T-Mark 4 at T-junction 2 a is configured by extending the transversal first white stripe 1 a about 2 inches from the zone boundaries of the intersection with a second white stripe 1 b. With this arrangement, the T-intermission 3 is provided. The color of the indicia of the T-intermission 3 must be different from the color of the white stripe but may be the same color of the pavement of the court. For example, in a tennis court configured of mainly green pavement with white stripes, T-intermission 3 could be made with a green color. The difference in visual perception in the T-intermission 3 assist the player, line judge and game spectators to distinguish easily if a ball 5 hits the T-intermission 3, in zone or out zone.

FIGS. 7A and 7B are directed to an exploded view of the T-junction 2 b with the T-intermission 3 of the present disclosure in accordance with the principles of the preferred third embodiment. The T-intermission 32 is configured to simulate part of the first white stripe 1 a and is not located at the intersection of the first white stripe 1 a and second white stripe 1 b. The dimension of the T-intermission 32 depends on the first white stripe 1 a dimensions, for example the first width W1 of a first white stripe 1 a defines at least one side of the T-intermission 32. The T-intermission 32 comprises particular indicia, wherein said particular indicia is distinctive from the first with stripe segment indicia and/or the court indicia but the indicia may be as the same color of the pavement of the court. As in the previous embodiments, the difference in visual perception due to the use of the T-intermission 32 assist the player, line judge and game spectators to distinguish easily if a ball 5 hits the T-intermission 32, in zone or out zone.

FIGS. 8A through 8C are exploded views of the different embodiments while the ball 5 is hitting floor in accordance with the principles of the preferred disclosure. As mentioned before, the corner, such as the corner of the center stripe is considered in bounds for both zones. FIG. 8A discloses the third embodiment wherein the T-intermission 32 assists to define the inbound boundaries. FIG. 8B discloses the first embodiment the T-intermission 3 and FIG. 8C is directed to a court comprising the T-mark 4, wherein both embodiments are configured to visually be distinctive from the boundaries lines of the playing zone assisting the judgment to determine is a ball 5 is in or out.

The material of the indicia of T-intermission 3 may vary depending on the material of the surface of the tennis court. It is preferred to use the same material for the indicia of the T-intermission 3 and the surface of the tennis court. Some of these materials are: acrylic, asphalt, or plastic. Preferably the material of the indicia of T-intermission 3 is rigid and attached to the surface and will not move or be deformed if the ball hits it or a player steps on it.

Further a T-intermission 3 with deformation properties and resilient properties may be used to distinguish the boundaries lines of a plying zone. As shown in FIGS. 9A and 9B a deformable T-intermission 3 which is hit by the ball 5 is deformed in accordance with the principles of the present embodiment. The use of a resilient material with deformation properties assists the line judge to double check if the T-intermission 3 was hit by the ball 5.

As shown in FIG. 1, a tennis court comprises a first surface comprising a first material; and a plurality of vertical lines and horizontal lines comprising a second surface; wherein the second surface comprises a second material; and each line in the plurality of vertical lines and horizontal lines has a width and a length. Moreover, a first set of the plurality of vertical lines and horizontal lines outlines a rectangular perimeter that sets the limit of the tennis court; and the first set of the plurality of vertical lines outlining the rectangular perimeter includes two parallel doubles sidelines, and the first set of horizontal lines outlining the rectangular perimeter includes two parallel baselines. As also shown in FIG. 1, a second set of the plurality of vertical lines and horizontal lines is located within the rectangular perimeter and is arranged to define at least two identical halves of the tennis court, each half comprising two parallel singles sidelines that intersect with each parallel baseline, a service line that intersects with each parallel singles sideline, and a center service line that intersects with the service line of each half.

Moreover, as shown in FIG. 4, the intersection between the two parallel singles sidelines with each parallel baseline may include a section of each parallel singles sideline that perpendicularly crosses the corresponding parallel baseline beyond the width of each parallel baseline, thus forming two T-junctions on each parallel baseline. Additionally, the intersection between the two parallel singles sidelines with each parallel baseline includes an indicia having a width equivalent to the width of the corresponding singles sidelines and having a length equivalent to the width of the corresponding baseline; the intersection between the service line of each half with each parallel singles sideline includes a section of the service line that perpendicularly crosses the corresponding parallel singles sideline beyond the width of the corresponding parallel singles sideline, thus forming two T-junctions on each parallel singles sideline; and the intersection between the service line with each parallel singles sideline includes an indicia having a width equivalent to the width of the service line and having a length equivalent to the width of the corresponding parallel singles sideline. Lastly, the intersection between the center service line with the service line of each half includes a section of the center service line that perpendicularly crosses each service line beyond the width of the corresponding service line, thus forming a T-junction on the corresponding service line, wherein the intersection between the center service line with the service line of each half includes an indicia having a width equivalent to the width of the center service line and having a length equivalent to the width of the service line. It should be noted that each indicia comprises the first material corresponding to the first surface; and the first surface and the second surface are visually different from each other.

FIGS. 10-17 relate to another aspect of the present disclosure involving a marker configured to be inserted into the intersecting lines of demarcation of a tennis court. The marker comprises a cross-piece C for marking the corners of a tennis court and is analogous to the embodiment shown in FIGS. 4, 6 and 8C. Although it is envisioned that the cross-piece C can be used on any surface, it is preferable that it be implemented on clay surfaces. In the case of tennis courts having a clay surface, it is commonly known that these courts have certain particularities with respect to the installation or marking of court lines. Usually, the lines in the clay court are marked down on the clay based on the dimensions and regulations issued by the International Tennis Federation (“ITF”) or the Association of Tennis Professionals (“ATP”). Once the court has been marked down, line tape is rolled down and secured with nails on top of the markings on the clay. In some instances, white plastic lines are inserted into the areas previously marked down on the court. These white plastic lines do not require nails to be secured on the clay; they are simply hammered or pushed down until the plastic line lies parallel to the clay surface. The cross-piece or device C for marking the corners is meant to be hammered or pushed down on the area or region corresponding to the T-junctions 2 a, 2 b, 2 c, until the top surface of the cross-piece or device C is leveled or lies parallel to the clay surface. Accordingly, the cross-piece C is meant to be inserted at the intersection between the singles sideline and the baseline; the intersection between center service line and the service line; and the intersection between service line and the singles sideline.

In a preferred embodiment, the cross-piece C is a monolithic structure manufactured from plastic or through the process of injection molding or 3-D printing. The color of the cross-piece C should preferably be white so that it matches the remaining demarcation lines of traditional tennis courts; but in alternate embodiments the cross-piece C may comprise a different color or combination of colors (e.g., different sections of the cross-piece having different colors). The cross-piece C has the shape of a cross having an opening or gap 0 at its point of intersection, wherein the opening O corresponds to an intersection of a line of demarcation on a tennis court. It should be noted, however, that in other embodiments the cross-piece C does not have the opening O; rather, it is a solid cross-piece without a gap or opening at its point of intersection, as shown in FIG. 17.

Particularly, the cross-piece C comprises a vertical section VS and a horizontal section HS that are perpendicular to each other. The vertical section VS and the horizontal section HS have the same width as the lines of demarcation of the tennis court. The vertical section VS is further subdivided into an upper panel UP and a bottom panel BP, wherein each panel includes a top surface TS1, TS2 and two legs UPL1, UPL2, BPL1, BPL2 extending perpendicularly from the ends of the corresponding top surface TS1, TS2. In other words, the first upper panel leg UPL1 extends perpendicularly from a first end of the first top surface TS1; the second upper panel leg UPL2 extends perpendicularly from a second end of the first top surface TS1; the first bottom panel leg BPL1 extends perpendicularly from a first end of the second top surface TS2; and the second bottom panel leg BPL2 extends perpendicularly from a second end of the second top surface TS2.

Similarly, the horizontal section HS is further subdivided into a left panel LP and a right panel RP, wherein each panel includes a top surface TS3, TS4 and two legs RPL1, BPL2, LPL1, LPL2 extending perpendicularly from the corresponding top surface TS1, TS2. In other words, the first right panel leg RPL1 extends perpendicularly from a first end of the third top surface TS3; the second right panel leg RPL2 extends perpendicularly from a second end of the third top surface TS3; the first left panel leg LPL1 extends perpendicularly from a first end of the fourth top surface TS4; and the second left panel leg LPL2 extends perpendicularly from a second end of the second top surface TS4. In another embodiment, the cross-piece C comprises a central panel CP with to top surface TS5 at its point of intersection (i.e., between the left and right panel and between the upper and bottom panel), rather than the opening O, as shown in FIG. 17. The central panel CP may have the same color as the remaining panels or o a different one. To identify the landing spot of the tennis ball, it is preferred that the color of the central panel CP be different from the color of the remaining panels.

Moreover, as shown in FIG. 14, an end of the first leg of the left panel LPL1 is fastened, connected, or attached to an end of the first leg of the upper panel UPL1, while an end of the second leg of the left panel LPL2 is fastened, connected, or attached to an end the first leg of the bottom panel BPL1. Similarly, an end of the first leg of the right panel RPL1 is fastened, connected, or attached to an end of the second leg of the upper panel UPL2, while an end of the second leg of the right panel RPL2 is fastened, connected, or attached to an end of the second leg of the bottom panel BPL2. This configuration or interaction between the ends of the legs of each panel is responsible for creating the opening O at the cross section of the cross-piece C. It should be noted that the legs of each panel may include a slanted or biased section SS or portion to facilitate the insertion or integration of the cross-piece C into the clay or particular surface.

The cross-piece C may optionally include support pieces SP1, SP2, SP3, SP4 to fortify or provide additional support to the connection between the legs of the cross-piece C. As shown in FIG. 14, the cross-piece C includes a first support piece SP1 at the intersection or connection between the first leg of the left panel LPL1 and the first leg the upper panel UPL1; a second support piece SP2 at the intersection or connection between the first leg of the right panel RPL1 and the second leg of the upper panel UPL2; a third support piece SP3 at the intersection or connection between the second leg of the left panel LPL2 and the first leg of the bottom panel BPL1; and a fourth support piece SP4 at the intersection or connection between the second leg of the right panel SPL2 and the second leg of the bottom panel BLP2. The support pieces SP1, SP2, SP3, SP4 may also include a slanted or biased section or portion (not shown) to facilitate the insertion or integration of the cross-piece C into the clay or particular surface.

With respect to the placement or location on the tennis court of the cross-piece C, it should be noted that the cross-piece C must be placed in the areas or T-junctions marked 2 a, 2 b, 2 c in FIG. 1. When placed in those areas, the opening O of the cross-piece C would correspond to the intersection between the singles sideline and corresponding baseline; to the intersection between the service line and the corresponding singles sideline; and to the intersection between the center service line and the corresponding service line. For example, FIG. 15, shows that the opening O of the cross-piece C corresponds to the intersection between the singles sideline and corresponding baseline. It should also be noted that the upper panel UP is analogous to the T-Mark 4 that extends about 2 inches from the zone boundaries (e.g., baseline, singles sideline, or service line) in T-junctions 2 a, 2 b and 2 c discussed for FIG. 6. Accordingly, the upper panel UP in cross-piece C is analogous to 1) the section of each parallel singles sideline that perpendicularly crosses the corresponding parallel baseline beyond the width of each parallel baseline; 2) the section of the service line that perpendicularly crosses the corresponding parallel singles sideline beyond the width of the corresponding parallel singles sideline; and 3) section of the center service line that perpendicularly crosses each service line beyond the width of the corresponding service line. This means that contrary to the remaining panels, the upper panel UP does not correspond to any of the lines in the tennis court. For this reason, only a portion of the vertical section VS (i.e., the bottom panel) corresponds to the lines of demarcation of the tennis court.

When the cross-piece C is inserted into the clay, as shown in FIG. 15, the opening O at the point of intersection will be filled with clay. In other words, the opening O servers an access point or provides visibility to the clay surface (or any other surface material depending on the type of court). As such, the clay acts as indicia that is visually different from the color of the white lines marking the boundaries of the court but retains the same color and is comprised of the same material as the surface of the court. This is analogous to the T-intermission 3 described in the embodiment shown in FIG. 4 and helps a judge to more easily identify if a ball falls in bounds or out-of-bounds. It should be noted that the upper panel UP is preferably shorter in length than the bottom panel BP of the vertical section VS. The upper panel UP should preferably have a length of two inches.

Once the cross-piece C is inserted into the court surface in areas or T-junctions marked 2 a, 2 b, 2 c, the remaining lines of the court are completed by inserting white plastic lines having the same width and color as the sections of the cross-piece C, and comprising the same material as the cross-piece C, until all lines have been completed. For example, if the surface is made of clay, the remaining lines would have to be inserted into the surface in the manner that is known in the art for inserting white plastic lines into courts having a clay surface. The white plastic lines must also be joined or fastened to the cross-piece C, so that they are positioned in close proximity to the corresponding panel BP, RP, LP of the cross-piece C. Note, however, that none of the white plastic lines are joined or fastened to the upper panel UP.

Lastly, it should be noted that while the preferred embodiment of the cross-piece C is a monolithic structure in which all sections or panels are seamlessly or continuously connected, the cross-piece C can also be comprised of separate pieces. For example, the upper panel UP, bottom panel BP, right panel RP and left panel LP can be independent pieces that are joined together via a locking mechanism LM. As shown in FIG. 16, the cross-piece C, may include a locking mechanism LM for locking or connecting the panels in the vertical section VS to the panels of the horizontal section HS. In this embodiment one section is mechanically fitted into the other.

In summary of the previous sections, the disclosure presented here is structurally innovative, presents advantages not available at the moment with blending system, complies with all new patent application requirements and is hereby lawfully submitted to the patent bureau for review and the granting of the commensurate patent rights.

While the invention has been described as having a preferred design, it is understood that many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art without materially departing from the novel teachings and advantages of this invention after considering this specification together with the accompanying drawings. Accordingly, all such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by this invention as defined in the following claims and their legal equivalents. In the claims, means-plus-function clauses, if any, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.

All of the patents, patent applications, and publications recited herein, and in the Declaration attached hereto, if any, are hereby incorporated by reference as if set forth in their entirety herein. All, or substantially all, the components disclosed in such patents may be used in the embodiments of the present invention, as well as equivalents thereof. The details in the patents, patent applications, and publications incorporated by reference herein may be considered to be incorporable at applicant's option, into the claims during prosecution as further limitations in the claims to patentable distinguish any amended claims from any applied prior art. 

What is claimed is:
 1. A tennis court marker configured to be inserted into the intersecting lines of demarcation of a tennis court, comprising: a cross-piece having the shape of a cross with an opening at its point of intersection; wherein the cross-piece includes a vertical section and a horizontal section that are perpendicular to each other; wherein the vertical section is subdivided into an upper panel and a bottom panel; wherein each panel in the vertical section includes a top surface; wherein the upper panel includes a first leg extending perpendicularly from a first end of the top surface of the upper panel and a second leg extending perpendicularly from a second end of the top surface of the upper panel; wherein the bottom panel includes a first leg extending perpendicularly from a first end of the top surface of the bottom panel and a second leg extending perpendicularly from a second end of the top surface of the bottom panel; wherein the horizontal section is subdivided into a left panel and a right panel; wherein each panel in the horizontal section includes a top surface; wherein the right panel includes a first leg extending perpendicularly from a first end of the top surface of the right panel and a second leg extending perpendicularly from a second end of the top surface of the right panel; wherein the left panel includes a first leg extending perpendicularly from a first end of the top surface of the left panel and a second leg extending perpendicularly from a second end of the top surface of the left panel; wherein an end of the first leg of the left panel is connected to an end of the first leg of the upper panel, wherein an end of the second leg of the left panel is connected to an end the first leg of the bottom panel, wherein an end of the first leg of the right panel is connected to an end of the second leg of the upper panel, and wherein an end of the second leg of the right panel is connected to an end of the second leg of the bottom panel, thereby creating the opening at the point of intersection of the cross-piece and providing access to and visibility to the surface of the tennis court.
 2. The tennis court marker of claim 1, wherein the legs in each panel include a slanted or biased portion to facilitate the insertion or integration of the cross-piece into the tennis court surface.
 3. The tennis court marker of claim 1, wherein the opening corresponds to an intersection on the lines of demarcation of the tennis court.
 4. The tennis court marker of claim 3, wherein the intersection corresponds to the intersection between a singles sideline and a baseline of the tennis court.
 5. The tennis court marker of claim 3, wherein the intersection corresponds to the intersection between a service line and a singles sideline of the tennis court.
 6. The tennis court marker of claim 3, wherein the intersection corresponds to the intersection between a center service line and a service line of the tennis court.
 7. The tennis court marker of claim 1, wherein the upper panel is shorter in length than the bottom panel.
 8. The tennis court marker of claim 1, wherein the cross-piece is a monolithic structure.
 9. The tennis court marker of claim 1, further comprising an interlocking mechanism for connecting the panels in the vertical section to the panels of the horizontal section.
 10. The tennis court marker of claim 1, wherein the vertical section and the horizontal section have the same width as the lines of demarcation of a tennis court.
 11. The tennis court marker of claim 1, wherein the first leg of the left panel is seamlessly connected to the end of the first leg of the upper panel, wherein the end of the second leg of the left panel is seamlessly connected to the end the first leg of the bottom panel, wherein the end of the first leg of the right panel is seamlessly connected to the end of the second leg of the upper panel, and wherein the end of the second leg of the right panel is seamlessly connected to the end of the second leg of the bottom panel.
 12. The tennis court marker of claim 1, wherein the connection between the first leg of the left panel and the first leg the upper panel includes a first support piece, the connection between the first leg of the right panel and the second leg of the upper panel includes a second support piece, the connection between the second leg of the left panel and the first leg of the bottom panel includes a third support piece, and the connection between the second leg of the right panel and the second leg of the bottom panel includes a third support piece.
 13. A tennis court marker configured to be inserted into the intersecting lines of demarcation of a tennis court, comprising: a cross-piece having the shape of a cross; wherein the cross-piece includes a vertical section and a horizontal section that are perpendicular to each other; wherein the vertical section is subdivided into an upper panel and a bottom panel; wherein each panel in the vertical section includes a top surface; wherein the upper panel includes a first leg extending perpendicularly from a first end of the top surface of the upper panel and a second leg extending perpendicularly from a second end of the top surface of the upper panel; wherein the bottom panel includes a first leg extending perpendicularly from a first end of the top surface of the bottom panel and a second leg extending perpendicularly from a second end of the top surface of the bottom panel; wherein the horizontal section is subdivided into a left panel and a right panel; wherein each panel in the horizontal section includes a top surface; wherein the right panel includes a first leg extending perpendicularly from a first end of the top surface of the right panel and a second leg extending perpendicularly from a second end of the top surface of the right panel; wherein the left panel includes a first leg extending perpendicularly from a first end of the top surface of the left panel and a second leg extending perpendicularly from a second end of the top surface of the left panel; wherein an end of the first leg of the left panel is connected to an end of the first leg of the upper panel, wherein an end of the second leg of the left panel is connected to an end the first leg of the bottom panel, wherein an end of the first leg of the right panel is connected to an end of the second leg of the upper panel, and wherein an end of the second leg of the right panel is connected to an end of the second leg of the bottom panel.
 14. The tennis court marker of claim 13, wherein the legs in each panel include a slanted or biased portion to facilitate the insertion or integration of the cross-piece into the tennis court surface.
 15. The tennis court marker of claim 13, wherein the cross-piece comprises a central panel between the left and right panel and between the upper and bottom panel.
 16. The tennis court marker of claim 15, wherein the central panel, right panel, left panel, upper panel and bottom panel have the same color.
 17. The tennis court marker of claim 15, wherein the central panel has a first color and the right panel, left panel, upper panel and bottom panel have a second color that is different from the first color. 